The present invention relates to novel diamide and acid anhydride applicable for synthesizing of a polyimide compositions and to production methods thereof. More particularly, the invention relates to novel diamines and acid anhydrides which include a cinnamoyl group or a derived cinnamoyl group have photo-reactivity and heat-reactivity which are inherent in the cinnamoyl group and are usable for synthesizing of polyimide.
Dimerization of cinnamic acid by ultraviolet radiation has been known for years. Therefore, it is conceivable that a useful photo-sensitive resin will be obtained by incorporating a cinnamoyl group into a polymer. Conventionally known as a polymer having a cinnamoyl group is polyvinyl cinnamate (polyvinyl having a cinnamoyl group) (Jpn. J. Appl. Phys., 31(1992), 2155, and J. Photopolymer Sci. and Tech. 8(1995), 257). The polyvinyl cinnamate is a useful photo-sensitive resin which becomes insoluble in a solvent when the cinnamoyl group is dimerized by light radiation (J. Appl. Polymer Sci., 2, 302(1959)), and used as a negative photo-sensitive resin.
However, the aforesaid polyvinyl cinnamate is poor in heat resistance and, hence, cannot be used in applications which require heat resistance.
Meanwhile, a reaction process is facilitated by first introducing a cinnamoyl group into a starting material of a polymer, i.e., a reactive monomer, and then polymerizing the monomer. However, no such reactive monomer is yet in existence.
Among a variety of organic polymers, polyimides and polyamides are particularly excellent resins which find wide applications in various fields ranging from the aerospace field to the electronic communications field because of their superior heat resistance, and have been expected to be applicable to photo-sensitive resins.
In general, starting materials for an aromatic polyimide are an aromatic amine and an acid dianhydride, and starting materials for an aromatic polyamide are an aromatic amine and an aromatic dicarboxylic acid or an aromatic dicarboxylic acid chloride. An aromatic acid dianhydride having a cinnamoyl group has not been known yet.
The aromatic amine is generally obtained by reducing an aromatic nitro compound. For production of a polyimide or polyamide having a cinnamoyl group, an aromatic amine having the cinnamoyl group is first obtained by reduction of a nitro compound having the cinnamoyl group, and then polymerization is carried out to afford the polyimide or polyamide. However, processes for the reduction of the aromatic nitro compound into the aromatic amine currently suffer from the following drawbacks. Further, few amines which have the cinnamoyl group and are usable as monomers for photo-sensitive resin materials have been known, and neither polyimide nor polyamide exists which has the cinnamoyl group and is usable as a photo-sensitive resin.
Common processes for reducing an aromatic nitro compound into an aromatic amine include: (1) reduction with a metal or a metal salt; (2) reduction with hydrazine; (3) hydrogenation with a Pd-activated charcoal catalyst; and the like.
Examples of the process (1) include reduction with tin chloride in a hydrochloric acid solution (tin- hydrochloric acid system), reduction with iron sulfate followed by neutralization with ammonia (iron sulfate-ammonia system), and reduction with metal iron in a solution (Bechamp reduction).
In these processes, however, precipitation of metal salts result from neutralization upon completion of the reaction, so that a very troublesome operation is required in isolation of the aromatic amine. In addition, these processes suffer from a problem such that breakage of ester linkage may occur due to the reaction under acidic conditions or a Michael addition may occur due to the reaction under alkaline conditions.
Examples of the process (2) include hydrogenation with a Pd-activated charcoal catalyst, and hydrogenation with a Raney nickel catalyst.
Among these processes, the hydrogenation with the Pd-activated charcoal catalyst is not preferred because a side reaction such as a Michael addition or decomposition of a nitro compound may occur. One example of the hydrogenation with the Raney nickel catalyst is described in Heiv. Chim. Actra., 24, 209E (1941), in which aminocinnamic acid is synthesized from nitrocinnamic acid with the use of hydrazine in the presence of the Raney nickel catalyst. However, if this system is applied to reduction of a nitrocinnamic acid derivative instead of nitrocinnamic acid, a side reaction such as a Michael addition may proceed.
In the process (3), reduction is generally allowed to proceed with the use of a Pd-activated charcoal catalyst in an organic solvent under a hydrogen atmosphere. With the use of an ordinary Pd-activated charcoal, even a double bond of a cinnamoyl group may be reduced.
As described above, it is very difficult to optimize the conditions for the reduction of the nitro compound, so that few amines having the cinnamoyl group have been isolated.
In order to solve the aforesaid problems, the present invention is directed to provide a method for preparing a novel amine having a cinnamoyl group or a derived cinnamoyl group by optimizing conditions for reduction of a nitro compound, such a novel amine having been considered impossible to prepare.
It is an object of the present invention to provide a novel diamine or a novel acid dianhydride to provide a novel polyimide composition having a cinnamoyl group or a derived cinnamoyl group.
It is another object of the invention to provide a novel polyimide composition prepared from a novel diamine or a novel acid dianhydride having a cinnamoyl group or a derived cinnamoyl group.
It is further another object of the invention to provide a method for producing a novel diamine having a cinnamoyl group or a derived cinnamoyl group.
As a result of intensive studies to provide a novel diamine, acid anhydride, and polyimide composition having a cinnamoyl group or a derived cinnamoyl group and exhibiting photo-sensitivity as well as photo-reactivity, the inventors of the present invention have attained the present invention.
A novel polyimide composition of the present invention comprises a cinnamoyl group incorporated in a main chain or a side chain.
A novel polyimide composition of the present invention comprises a monomer unit of the general formula (1) in a proportion of not smaller than 1% by weight: 
wherein X is a tetravalent organic group, and W is a divalent organic group selected from divalent organic groups represented by the formulae (1-a), (1-b), (1-c), (1-d), (1-e) and (1-f): 
In the novel polyimide composition of the invention, X in the general formula (1) represents one or two or more kinds of tetravalent organic groups which each comprise one to three aromatic rings or an aliphatic ring.
In the novel polyimide composition of the invention, V in the formula (1-a) represents a group selected from H, CH3, F, Cl, Br and CH3Oxe2x80x94, and A is a divalent organic group selected from the following groups: 
wherein V represents H, CH3, F, Cl, Br or CH3Oxe2x80x94.
In the novel polyimide composition of the invention, E and G in the formula (1-b) each represent a group selected from H, CH3, F, Cl, Br and CH3Oxe2x80x94, and D1 is a divalent organic group selected from the following groups: 
wherein w is an integer from 1 to 40, and V represents H, CH3, F, Cl, Br or CH3Oxe2x80x94.
In the novel polyimide composition of the invention, V in the formula (1-c) each represent H, CH3, F, Cl, Br or CH3Oxe2x80x94, and J1 represents xe2x80x94CH2xe2x80x94, xe2x80x94(CH2)mxe2x80x94Oxe2x80x94 or xe2x80x94(CH2)nxe2x80x94OCOxe2x80x94, wherein m=1 to 15 and n=1 to 15.
In the novel polyimide composition of the invention, M and P in the formula (1-d), which may be the same or different, each represent a divalent organic group selected from the following groups: 
wherein w is an integer from 1 to 40, and V each represent H, CH3, F, Cl, Br or CH3Oxe2x80x94.
In the novel polyimide composition of the invention, V in the formula (1-e) each represents H, CH3, F, Cl, Br or CH3Oxe2x80x94, and T and S, which may be the same or different, each represent a divalent organic group selected from the following groups: 
wherein w is an integer from 1 to 40, and V each represent H, CH3, F, Cl, Br or CH3Oxe2x80x94.
In the novel polyimide composition, V in the formula (1-f) represents H, CH3, F, Cl, Br or CH3Oxe2x80x94, p=1 to 3, q=1 to 3, and Y represents a trivalent organic group selected from the following groups: 
wherein V represents H, CH3, F, Cl, Br or CH3Oxe2x80x94, r=1 to 3, n=1 to 20, W represents a divalent organic group selected from xe2x80x94CH2xe2x80x94, xe2x80x94(CH2)mxe2x80x94Oxe2x80x94 (wherein m=1 to 15) and xe2x80x94(CH2)kxe2x80x94OCOxe2x80x94 (wherein k=1 to 20 (kxe2x89xa02)).
Another novel polyimide composition of the present invention comprises a monomer unit of the general formula (2) in a proportion of not smaller than 1% by weight: 
wherein Wxe2x80x2 represents a divalent organic group, and Xxe2x80x2 is a group represented by one of the following formulae (2-a) and (2-b): 
wherein B and D each represent a divalent organic group, and V represents H, CH3, F, Cl, Br or CH3Oxe2x80x94.
In the novel polyimide composition of the invention, B in the formula (2-a) represents a divalent organic group selected from xe2x80x94COOxe2x80x94, xe2x80x94OCOxe2x80x94, xe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94Exe2x80x94Oxe2x80x94, xe2x80x94COOxe2x80x94Exe2x80x94OCOxe2x80x94, xe2x80x94Oxe2x80x94Exe2x80x94OCOxe2x80x94, xe2x80x94Oxe2x80x94Exe2x80x94COOxe2x80x94 and xe2x80x94OOCCHxe2x95x90CHxe2x80x94 wherein E represents xe2x80x94CmH2mxe2x80x94 (wherein m represents an integer from 1 to 20), a benzene ring, a naphthalene ring or a biphenyl.
In the novel polyimide composition of the invention, D in the formula (2-a) represents a single bond (xe2x80x94) or a divalent organic group selected from xe2x80x94Fxe2x80x94OCOxe2x80x94 and xe2x80x94Fxe2x80x94Oxe2x80x94 wherein F represents xe2x80x94CmH2mxe2x80x94 (wherein m represents an integer from 1 to 20), a benzene ring or a naphthalene ring.
In the novel polyimide composition of the invention, G in the formula (2-b) represents a trivalent organic group, and J represents H, CH3, F, Cl, Br or CH3Oxe2x80x94.
In the novel polyimide composition of the invention, G in the formula (2-b) represents one of the following groups: 
wherein K represents xe2x80x94CnH2nxe2x88x921xe2x80x94 (wherein n represents an integer from 1 to 20), a benzene ring, a naphthalene ring or a biphenyl.
A novel diamine of the present invention is a diamine represented by the general formula (3): 
wherein A represents a divalent organic group selected from the following groups: 
wherein V represents H, CH3, F, Cl, Br or CH3Oxe2x80x94.
Another novel diamine of the present invention is a diamine represented by the general formula (4): 
wherein D1 represents a divalent organic group selected from the following groups: 
wherein w represents an integer from 1 to 40, and V represents H, CH3, F, Cl, Br or CH3Oxe2x80x94.
Further another diamine of the present invention is a diamine represented by the general formula (5): 
wherein V each represents a group selected from H, CH3, F, Cl, Br and CH3Oxe2x80x94, and J1 represents a divalent organic group selected from xe2x80x94CH2xe2x80x94, xe2x80x94(CH2)mxe2x80x94Oxe2x80x94 (wherein m=1 to 15) and xe2x80x94(CH2)nxe2x80x94OCOxe2x80x94 (wherein n=1 to 15).
Still another diamine of the present invention is a diamine represented by the general formula (6): 
wherein M and P, which may be the same or different, each represent a divalent organic group selected from the following groups: 
wherein w represents an integer from 1 to 40, and V each represents H, CH3, F, Cl, Br or CH3Oxe2x80x94.
Further another diamine of the present invention is a diamine represented by the general formula (7): 
wherein T and S, which may be the same or different, each represent a divalent organic group selected from the following groups: 
wherein w represents an integer from 1 to 40, and V each represents H, CH3, F, Cl, Br or CH3Oxe2x80x94.
Still another diamine of the present invention is a diamine represented by the general formula (8): 
wherein V represents H, CH3, F, Cl, Br or CH3Oxe2x80x94, and Y represents a trivalent organic group selected from the following groups: 
wherein R and S may be the same or different, w represents an integer from 1 to 40, and T and V each represent H, CH3, F, Cl, Br or CH3Oxe2x80x94.
A novel acid dianhydride of the present invention is an acid dianhydride represented by the following general formula (9): 
wherein B and D2each represent a divalent organic group, and A represents H, CH3, F, Cl, Br or CH3Oxe2x80x94.
In the novel acid dianhydride of the invention, B in the general formula (9) represents a divalent organic group selected from xe2x80x94COOxe2x80x94, xe2x80x94OCOxe2x80x94, xe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94Exe2x80x94Oxe2x80x94, xe2x80x94COOxe2x80x94Exe2x80x94OCOxe2x80x94, xe2x80x94Oxe2x80x94Exe2x80x94OCOxe2x80x94, xe2x80x94Oxe2x80x94Exe2x80x94COOxe2x80x94 and xe2x80x94OOCxe2x95x90CHxe2x95x90CHxe2x80x94 wherein E represents xe2x80x94CmH2mxe2x80x94 (wherein m represents an integer from 1 to 20), a benzene ring, a naphthalene ring, or a biphenyl.
In the novel acid dianhydride of the invention, D2in the general formula (9) represents a single bond (xe2x80x94) or a divalent organic group selected from xe2x80x94Fxe2x80x94OCOxe2x80x94 and xe2x80x94Fxe2x80x94Oxe2x80x94 wherein F represents xe2x80x94CmH2mxe2x80x94 (wherein m represents an integer from 1 to 20), a benzene ring or a naphthalene ring.
Another novel acid dianhydride of the present invention is an acid dianhydride represented by the general formula (10): 
wherein J represents H, CH3, F, Cl, Br or CH3Oxe2x80x94.
In the novel acid dianhydride of the invention, G in the general formula (10) represents one of the following groups: 
wherein K represents CnH2nxe2x88x921 (wherein n represents an integer from 1 to 20), a benzene ring, a naphthalene ring or a biphenyl.
An aromatic amine preparation method according to the present invention is based on hydrogenation with a Pt-carbon-black catalyst.
Another aromatic amine preparation method according to the present invention is based on hydrogenation with a Pt-activated charcoal catalyst whose selective activity for a nitro group is enhanced by a metal selected from Fe, Na, Cu and Ni.
Novel polyimide compositions according to the present invention are characterized by a cinnamoyl group or a derived cinnamoyl group incorporated therein and by photo-reactivity and heat-reactivity which are inherent in the cinnamoyl group. The novel diamines and acid dianhydrides according to the present invention are materials to be mainly used for production of the aforesaid novel polyimide compositions having the cinnamoyl group, and each have the cinnamoyl group or the derived cinnamoyl group incorporated in a main chain or side chain thereof.
Although exemplary structures of the novel polyamide compositions of the present invention will be described by way of an embodiment, the structures of the polyimide compositions are not particularly limited as long as the cinnamoyl group is incorporated therein.
Examples of the polyimide compositions of the present invention will hereinafter be described, the structures of which are not particularly limited as long as the cinnamoyl group is incorporated in a main chain or a side chain.
A polyimide composition having a cinnamoyl group incorporated in a diamine residue comprises a monomer unit of the general formula (1) in a proportion of not smaller than 1% by weight: 
wherein X is a tetravalent organic group, and W is a divalent organic group selected from divalent organic groups represented by the formulae (1-a), (1-b), (1-c), (1-d), (1-e) and (1-f): 
A polyimide composition including a cinnamoyl group in an acid dianhydride residue comprises a monomer unit of the general formula (2) in a proportion of not smaller than 1% by weight: 
wherein Xxe2x80x2 is a group represented by one of the formulae (2-a) and (2-b): 
and Wxe2x80x2 represents a divalent organic group.
An explanation will herein after be given to the polyimide compositions each including a cinnamoyl group in accordance with the present invention and to production methods therefor.
Exemplary production methods for a polyimide having a cinnamoyl group in a diamine residue thereof include: (1) a method in which a diamine having a cinnamoyl group is first synthesized and then reacted with a given acid dianhydride for preparation of a polyamic acid, which is dehydrated for ring closure for preparation of the polyimide; and (2) a method in which a diol-terminated polyimide oligomer is reacted with a dicarboxylic acid or a diacid chloride to form ester linkage for polymerization, thereby preparing the polyimide composition.
An explanation will first be given to the polyimide composition production method (1) using a diamine having a cinnamoyl group.
The novel polyimide composition wherein W in the general formula (1) is represented by the formula (1-a), more specifically, which comprises a monomer unit represented by the following formula: 
is employed as an example for explanation of a specific polyimide composition production method according to the present invention.
A diamine as a material for the novel polyimide composition wherein W in the general formula (1) is represented by the formula (1-a) is represented by the general formula (3): 
wherein V represents H, CH3, F, Cl, Br or CH3Oxe2x80x94, and A represents a divalent organic group.
The diamine can be obtained by reacting a cinnamic acid derivative or a cinnamoyl chloride derivative with a nitro compound having a hydroxyl group to afford a dinitro compound and then reducing the dinitro compound.
More specifically, the cinnamic acid derivative is represented by the formula (1-2): 
wherein V represents H, CH3, F, Cl, Br or CH3Oxe2x80x94.
The cinnamoyl chloride derivative is represented by the formula (1-3): 
wherein V represents H, CH3, F, Cl, Br or CH3Oxe2x80x94.
The nitro compound having a hydroxyl group is represented by the formula (1-4):
O2Nxe2x80x94Axe2x80x94OHxe2x80x83xe2x80x83(1-4)
wherein A represents a divalent organic group.
These compounds are reacted with each other to afford a dinitro compound represented by the formula (1-5): 
wherein V represents H, CH3, F, Cl, Br or CH3Oxe2x80x94.
In the formulae (1-4) and (1-5), A is a divalent organic group, which is not particularly limited but examples thereof include the following groups: 
Next, conditions for the reduction of the dinitro compound will be described.
Exemplary methods for reduction of an aromatic nitro compound into an aromatic amine include: (1) reduction with a metal or a metal salt; (2) reduction with hydrazine; and (3) hydrogenation with the use of a Pd-activated charcoal catalyst. Basically, any of these reduction methods can be employed for the preparation of the aromatic amine according to the present invention.
However, since the aromatic nitro compound to be employed in the invention has a double bond attributed to the cinnamoyl group, selection of severe reduction conditions may result in reduction of the double bond. Further, reduction under strong acidic conditions may result in breakage of ester linkage, and reduction under alkaline conditions may result in a Michael addition. Therefore, the reduction conditions should be optimized.
In the present invention, the dinitro compound is subjected to the Bechamp reduction or hydrogen reduction with the use of a Pt-carbon black catalyst or a Pt-activated charcoal catalyst having a selective activity enhanced by iron or the like to afford a compound of the general formula (3) in a high yield: 
wherein A is a divalent organic group, and V represents H, CH3, F, Cl, Br or CH3Oxe2x80x94.
In the present invention, the xe2x80x9cPt-activated charcoalxe2x80x9d is a catalyst comprising activated charcoal and platinum carried thereon, and the xe2x80x9cPt-carbon blackxe2x80x9d is a catalyst comprising carbon black and platinum carried thereon.
In the reduction method suitable for the reduction of the dinitro compound, it is particularly preferred to employ a reduction catalyst comprising an activated charcoal carrier, and Pt carried thereon, more effectively a carbon black carrier and Pt carried thereon. The inventors have newly found that the reaction selectivity for a nitro group is remarkably enhanced by employing the Pt-carbon black catalyst or the selectivity-enhanced Pt-activated charcoal catalyst for the hydrogen reduction of the nitro compound having the cinnamoyl group in an organic solvent. The inventors have successfully obtained the intended novel amine having the cinnamoyl group from the nitro compound in a very high yield with the use of the reduction catalyst.
The Pt-carbon black catalyst is preferred, because the nitro group is preferentially reduced with the use of the Pt-carbon black catalyst with virtually no double bond reduction in the reduction system to afford the intended diamine in a high yield. A Pt-carbon black catalyst containing a metal such as Fe, Na, Cu or Ni also provides an excellent effect in the reaction selectivity for the nitro group. A Pt-carbon black catalyst containing Fe is preferred because it ensures a particularly high reaction selectivity.
The activated charcoal, though offering a lower reaction selectivity than the carbon black, may be used as the carrier. In this case, a Pt-activated charcoal catalyst containing Fe, Na or the like is preferred because it provides a further excellent effect in the reaction selectivity for the nitro group.
In another reduction method, a Pd-activated charcoal catalyst may be employed. The Pd-activated charcoal catalyst for the reduction provides a high reaction activity to reduce the carbon-carbon double bond in the cinnamoyl group, so that a catalyst poison such as sulfur, sulfur dioxide or carbon monoxide may be added to the catalyst to ensure a reaction selectivity for the nitro group. Thus, the novel diamine according to the invention can be prepared. The term xe2x80x9ccatalyst poisonxe2x80x9d herein means a substance which is irreversibly adsorbed on active sites of the catalyst to deactivate the function as the catalyst.
Exemplary methods for hydrogenation include: a method in which hydrogen gas is directly blown into an organic solvent; a method in which the reaction is allowed to proceed at an atmospheric pressure under a hydrogen atmosphere; and a method in which the reaction is allowed to proceed in a pressure-proof reaction vessel such as an autoclave in which hydrogen gas is filled under applying pressure.
The reaction is preferably allowed to proceed at a temperature ranging from a room temperature to approximately 120xc2x0 C. If the reaction temperature is not lower than 180xc2x0 C., the breakage of the double bond of the cinnamoyl group may result. Therefore, it is necessary to carry out the reaction at a temperature lower than 180xc2x0 C. A reaction temperature lower than a room temperature is not preferred from an industrial viewpoint, because a longer reaction time is required though the reaction may proceed at such a temperature.
The Pt-carbon black or Pt-activated charcoal catalyst contains platinum in a concentration of approximately 0.1 to 40% by weight, and provides a catalytic effect if the platinum concentration is not lower than 0.1%. The reaction rate tends to increase as the platinum concentration becomes higher. Since platinum is a precious metal, the catalyst to be used preferably has a platinum concentration of about 1 to 20%. The Pt-carbon black or Pt-activated charcoal catalyst may be used in a dry state or in a moistened state and, in either state, provides the same catalytic effect. The use of the catalyst in the moistened state is preferred from an industrial viewpoint, because handling of the catalyst is easy without scattering of particles of the catalyst.
The solvent to be used for the reduction is not particularly limited as long as the solvent is capable of dissolving the diamine and the dinitro compound therein and does not hinder the reaction. Examples of the solvent includes alcohols, aromatic solvents such as dioxane, toluene and xylene, sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide, formamide solvents such as N,N-dimethylformamide and N,N-diethylformamide, acetamide solvents such as N,N-dimethylacetamide and N,N-diethylacetamide, pyrrolidone solvents such as N-methyl-2-pyrrolidone and N-vinyl-2-pyrrolidone, phenol solvents such as phenol, o-, m- or p-cresol, xylenol, halogenated phenols and catechol, hexamethylphosphoramide, xcex3-butyrolactone, and any other solvents which are capable of dissolving the diamine and the dinitro compound and do not hinder the reaction.
One of the reduction methods suitable for the reduction of the dinitro compound is the Bechamp reduction method. According to this method, Fe powder is added to the dinitro compound in a solvent, and the resulting mixture is heated at a temperature not higher than 130xc2x0 C. for the reduction. Any of the solvents described above may be used as the solvent in this method. Particularly, acetic acid, alcohols, dioxane and the like are preferred.
The novel amine having the cinnamoyl group can be prepared in a very high yield with the use of the reduction catalyst having a high selective activity for the nitro group by any of the aforesaid methods. Since the novel amine according to the invention has the cinnamoyl group, the cinnamoyl group can be introduced into polymers such as polyamides and polyimides having superior properties by employing the amine as a starting material. Thus, these polymers will find wider applications as thermosetting resins and photo-sensitive reins. Further, the amine can be obtained at a high purity and in a high yield, so that isolation and purification steps can be omitted. This is economically advantageous, because the polyimide/polyamide production step can directly follow the amine preparation step.
An explanation will next be given to a method for synthesizing a polyimide represented by the general formula (1) from the diamine obtained in the aforesaid manner.
The diamine of the general formula (3) obtained in the aforesaid manner and another kind of diamine are reacted with an acid dianhydride in an organic polar solvent to afford a polyamic acid.
Examples of the organic polar solvent to be used for the reaction for the preparation of the polyamic acid include sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide, formamide solvents such as N,N-dimethylformamide and N,N-diethylformamide, acetamide solvents such as N,N-dimethylacetamide and N,N-diethylacetamide, pyrrolidone solvents such as N-methyl-2-pyrrolidone and N-vinyl-2-pyrrolidone, phenol solvents such as phenol, o-, m- or p-cresol, xylenol, halogenated phenols and catechol, hexamethylphosphoramide, and xcex3-butyrolactone. These are preferably used either alone or in combination. Some aromatic solvents such as xylene and toluene may be used.
The acid dianhydride to be used in the present invention is not particularly limited, but examples thereof include: aliphatic or alicyclic tetracarboxylic dianhydrides such as butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 3,5,6-tricarboxynorbornane-2-acetic dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 5-(2,5-dioxotetrahydrofural)-3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride and bicyclo[2,2,2]-oct-7-ene-2,3,5,6-tetracarboxylic dianhydride; aromatic tetracarboxylic dianhydrides such as pyromellitic dianhydride, 3, 3xe2x80x2,4, 4xe2x80x2-benzophenonetetracarboxylic dianhydride, 3,3xe2x80x2,4, 4xe2x80x2-biphenylsulfonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3xe2x80x2,4,4xe2x80x2-biphenylethertetracarboxylic dianhydride, 3,3xe2x80x2,4,4xe2x80x2-dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3xe2x80x2,4,4xe2x80x2-tetraphenylsilanetetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic dianhydride, 4,4xe2x80x2-bis(3,4-dicarboxyphenoxy)diphenyl sulfide dianhydride, 4,4xe2x80x2-bis(3,4-dicarboxyphenoxy)diphenyl sulfone dianhydride, 4,4xe2x80x2-bis(3,4-dicarboxyphenoxy)diphenylpropane dianhydride, 3,3xe2x80x2,4,4xe2x80x2-perfluoroisopropylidenediphthalic dianhydride, 3,3xe2x80x2,4,4xe2x80x2-biphenyltetracarboxylic dianhydride, bis(phthalic acid)phenylphosphine oxide dianhydride, p-phenylene-bis(triphenylphthalic acid) dianhydride, m-phenylene-bis(triphenylphthalic acid) dianhydride, bis(triphenylphthalic acid)-4,4xe2x80x2-diphenyl ether dianhydride, bis(triphenylphthalic acid)-4,4xe2x80x2-diphenylmethane dianhydride; aliphatic tetracarboxylic anhydrides having aromatic ring such as 1,3,3a,4,5,9b-hexahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-5-methyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-8-methyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione, compounds represented by the following general formula (11): 
(wherein R1 represents a divalent organic group having aromatic ring, and R2 and R3 each represent a hydrogen atom or an alkyl group), and compounds represented by the following general formula (12): 
wherein R4 represents a divalent organic group having aromatic ring, and R5 and R6 each represent a hydrogen atom or an alkyl group. These tetracarboxylic dianhydrides may be used either alone or in combination of two or more.
Any of various diamines may be used in addition to the aforesaid diamine having the cinnamoyl group for the production of the polyimide composition of the present invention. The diamine is not particularly limited, but examples thereof include: aromatic diamines such as p-phenylenediamine, m-phenylenediamine, 4,4xe2x80x2-diaminodiphenylmethane, 4,4xe2x80x2-diaminodiphenylethane, 4,4xe2x80x2-diaminodiphenyl ether, 4,4xe2x80x2-diaminodiphenyl sulfide, 4,4xe2x80x2-diaminodiphenyl sulfone, 1,5-diaminonaphthalene, 3,3xe2x80x2-dimethyl-4,4xe2x80x2-diaminobiphenyl, 5-amino-1-(4xe2x80x2-aminophenyl)-1,3,3-trimethylindan, 6-amino-1-(4xe2x80x2-aminophenyl)-1,3,3-trimethylindan, 4,4xe2x80x2-diaminobenzanilide, 3,5-diamino-3xe2x80x2-trifluoromethylbenzanilide, 3,5-diamino-4xe2x80x2-trifluoromethylbenzanilide, 3,4xe2x80x2-diaminodiphenyl ether, 2,7-diaminofluorene, 2,2xe2x80x2-bis (4-aminophenyl) hexafluoropropane, 4,4xe2x80x2-methylene-bis(2-chloroaniline), 2,2xe2x80x2,5,5xe2x80x2-tetrachloro-4,4xe2x80x2-diaminobiphenyl, 2,2xe2x80x2-dichloro-4, 4xe2x80x2-diamino-5,5xe2x80x2-dimethoxybiphenyl, 3,3xe2x80x2-dimethoxy-4,4xe2x80x2-diaminobiphenyl, 4,4xe2x80x2-diamino-2,2xe2x80x2-bis(trifluoromethyl)biphenyl, 2,2xe2x80x2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 1,4-bis(4-aminophenoxy)benzene, 4,4xe2x80x2-bis(4-aminophenoxy)-biphenyl, 1,3xe2x80x2-bis(4-aminophenoxy)benzene, 9,9-bis(4-aminophenyl)fluorene, 4,4xe2x80x2-(p-phenyleneisopropylidene)bisaniline, 4,4xe2x80x2-(m-phenyleneisopropylidene) bisaniline, 2,2xe2x80x2-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]-hexafluoropropane, 4,4xe2x80x2-bis[4-(4-amino-2-trifluoromethyl)phenoxy]-octafluorobi phenyl; aromatic diamines, such as diaminotetraphenylthiophene, which have two amino groups bonded to an aromatic ring, and a hetero atom other than the nitrogen atoms of the amino groups; aliphatic and alicyclic diamines such as metaxylylene diamine, 1,3-propane diamine, tetramethylenediamine, pentamethylenediamine, octamethylenediamine, nonamethylenediamine, 1,7-diaminoheptamethylenediamine, 1,4-diaminocyclohexane, isophorone diamine, tetrahydrodicyclopentadienylene diamine, hexahydro-4,7-methanoindanilenedimethylene diamine, tricyclo[6,2,1,02.7]-undecylenedimethyl diamine, 4,4xe2x80x2-methylenebis(cyclohexylamine); mono-substituted phenylenediamines represented by the following general formula (13): 
(wherein R7 represents a divalent organic group selected from xe2x80x94Oxe2x80x94, xe2x80x94COOxe2x80x94, xe2x80x94OCOxe2x80x94, xe2x80x94CONHxe2x80x94 and xe2x80x94COxe2x80x94, and R8 represents a monovalent organic group having a steroid group); and compounds represented by the following general formula (14): 
(wherein R9 represents a hydrocarbon group having 1 to 12 carbons, y is an integer from 1 to 3, and z is an integer from 1 to 20). These diamine compounds may be used either alone or in combination of two or more in addition to 1% of the diamine having the cinnamoyl group.
The polyamic acid obtained as a precursor of the polyimide in the aforesaid manner is thermally or chemically imidized to afford the polyimide composition having the cinnamoyl group. The thermal imidization herein means dehydration imidization which is achieved by adding a tertiary amine and an azeotropic solvent to the aforesaid polyamic acid copolymer. The chemical imidization herein means imidization which is achieved by adding a dehydrating agent and a tertiary amine as a catalyst in amounts not smaller than the stoichiometric amounts to the polyamic acid polymer or a solution thereof, and heating the resulting mixture.
Examples of the dehydrating agent include aliphatic acid anhydrides such as acetic anhydride, and aromatic acid anhydrides. Examples of the catalyst include aliphatic tertiary amines such as triethylamine, aromatic tertiary amines such as dimethylaniline, and heterocyclic tertiary amines such as pyridine, picoline and isoquinoline.
In general, the thermal imidization involves heating at a temperature not lower than 150xc2x0 C. At a temperature not lower than 180xc2x0 C., however, the carbon-carbon double bond in the cinnamoyl group or derived cinnamoyl group may undergo a reaction in which the double bond is broken so that the carbons may form bonds with other carbon-carbon double-bond or oxygen. In the present invention, therefore, the thermal imidization with the use of the aforesaid tertiary amine is preferably carried out under temperature conditions of 150xc2x0 C. to 180xc2x0 C. to afford the polyimide having the cinnamoyl group. Where the chemical imidization with the use of the acid anhydride is employed in combination with the thermal imidization, the imidization reaction can be carried out at a lower temperature.
The polyamic acid preferably has a weight-average molecular weight of 5,000 to 1,000,000. If the molecular weight is smaller than 5,000, the resulting polyimide composition will have a smaller molecular weight. Therefore, the polyimide composition, if used as it is, is not practical as a photo-reactive resin because of its brittleness. Conversely, if the weight-average molecular weight is greater than 1,000,000, a varnish of the polyamic acid will have an excessively high viscosity, so that the handling thereof is difficult.
Thus, the novel polyimide composition according to the present invention is produced.
Any of various organic additives, inorganic fillers and various reinforcement materials may be added to the polyimide composition.
Next, an explanation will be given to production methods for the respective polyimide compositions, wherein W in the general formula (1) is represented by the formulae (1-b) to (1-e), from diamines each having a cinnamoyl group. The method and conditions for the reduction of the dinitro compound and the method for the production of the polyimide are substantially the same as described above for the polyimide composition of the general formula (1).
A diamine to be used as a starting material for the novel polyimide composition wherein W in the general formula (1) is represented by the formula (1-b), more specifically, which comprises a monomer unit represented by the following formula: 
is represented by the general formula (4): 
The diamine can be prepared by reducing a dinitro compound which is prepared by reacting a nitrocinnamic acid derivative or a nitrocinnamoyl chloride derivative with a diol.
More specifically, the nitrocinnamic acid derivative is represented by the formula (2-2): 
wherein V each represents H, CH3, F, Cl, Br or CH3Oxe2x80x94.
The nitrocinnamoyl chloride derivative is represented by the formula (2-3): 
wherein E and G each represent H, CH3, F, Cl, Br or CH3Oxe2x80x94.
The diol is a compound having two hydroxyl groups and represented by the formula (2-4):
xe2x80x83HOxe2x80x94D1xe2x80x94OHxe2x80x83xe2x80x83(2-4)
wherein D1 represents a divalent organic group.
These compounds are reacted with each other to afford a dinitro compound represented by the formula (2-5): 
wherein D1 represents a divalent organic group, and V each represent H, CH3, F, Cl, Br or CH3Oxe2x80x94. The dinitro compound is reduced to afford the diamine.
In the formulae (2-4) and (2-5), D1 is a divalent organic group, which is not particularly limited, but examples thereof include the following groups: 
wherein V represents H, CH3, F, Cl, Br or CH3Oxe2x80x94.
A diamine to be used as a starting material for the novel polyimide composition wherein W in the general formula (1) is represented by the formula (1-c), more specifically, which comprises a monomer unit represented by the following formula: 
is represented by the general formula (5): 
wherein J1 represents a divalent organic group, and V, which may be the same or different, each represent H, CH3, F, Cl, Br or CH3Oxe2x80x94.
For preparation of the diamine, a cinnamic acid derivative represented by the formula (3-2): 
(wherein V represents H, CH3, F, Cl, Br or CH3Oxe2x80x94) or a cinnamoyl chloride derivative represented by the formula (3-3): 
(wherein V represents H, CH3, F, Cl, Br or CH3Oxe2x80x94) is reacted with a nitro compound having a hydroxyl group and represented by the formula (3-4): 
(wherein V represents H, CH3, F, Cl, BrorCH3Oxe2x80x94, and J1 represents a divalent organic group) to afford a dinitro compound represented by the formula (3-5): 
(wherein J1 represents a divalent organic group, and V each represent H, CH3, F, Cl, Br or CH3Oxe2x80x94).
The dinitro compound of the formula (3-5) thus prepared is reduced to afford the diamine represented by the general formula (5).
In the formulae (3-4) and (3-5), J1 is a divalent organic group, which is not particularly limited but may be selected from xe2x80x94CH2xe2x80x94(CH2)mxe2x80x94 (wherein m=1 to 15), xe2x80x94Oxe2x80x94(CH2)nxe2x80x94 (wherein n=1 to 15) and xe2x80x94OCOxe2x80x94.
A diamine to be used as a starting material for the novel polyimide composition wherein W in the general formula (1) is represented by the formula (1-d), more specifically, which comprises a monomer unit represented by the following formula: 
is represented by the general formula (6): 
A cinnamic acid derivative represented by the general formula (4-2): 
(wherein V represents H, CH3, F, Cl, Br or CH3Oxe2x80x94) or a cinnamoyl chloride derivative represented by the formula (4-3): 
(wherein V represents H, CH3, F, Cl, Br or CH3Oxe2x80x94) is reacted with a nitro compound having a hydroxyl group and represented by the formula (4-4):
O2Nxe2x80x94Mxe2x80x94OH or O2Nxe2x80x94Pxe2x80x94OHxe2x80x83xe2x80x83(4-4)
(wherein M and P each represent a divalent organic group) to afford a dinitro compound represented by the formula (4-5): 
(wherein M and P each represent a divalent organic group, and V represents H, CH3, F, Cl, Br or CH3Oxe2x80x94), and the dinitro compound is reduced to afford the diamine.
In the formulae (4-4) and (4-5), M and P are divalent organic groups, which are not particularly limited but may be selected from the following groups: 
wherein w is an integer from 1 to 40, and V represents H, CH3, F, Cl, Br or CH3Oxe2x80x94.
A diamine to be used as a starting material for the novel polyimide composition wherein W in the general formula (1) is represented by the formula (1-e), more specifically, which comprises a monomer unit represented by the following formula: 
is represented by the general formula (7): 
For preparation of the diamine, a phenylenediacrylic acid derivative represented by the formula (5-2): 
(wherein V represents H, CH3, F, Cl, Br or CH3Oxe2x80x94) or a phenylenediacrylic dichloride derivative represented by the formula (5-3): 
(wherein V represents H, CH3, F, Cl, Br or CH3Oxe2x80x94) is reacted with a nitro compound having a hydroxyl group and represented by the formula (5-4):
O2Nxe2x80x94Txe2x80x94OH or HOxe2x80x94Sxe2x80x94NO2xe2x80x83xe2x80x83(5-4)
(wherein T and S each represent a divalent organic group) to afford a dinitro compound represented by the formula (5-5): 
(wherein T and S each represent a divalent organic group, and V represents H, CH3, F, Cl, Br or CH3Oxe2x80x94).
The dinitro compound thus prepared is reduced to afford the diamine.
In the formulae (5-4) and (5-5), T and S are divalent organic groups, which are not particularly limited but may be selected from the following groups: 
wherein w is an integer from 1 to 40, and V represents H, CH3, F, Cl, Br or CH3Oxe2x80x94.
A diamine to be used as a starting material for the novel polyimide composition wherein W in the general formula (1) is represented by the formula (1-f), more specifically, which comprises a monomer unit represented by the following formula: 
is represented by the general formula (8): 
wherein Y represents a trivalent organic group, V represents H, CH3, F, Cl, Br or CH3Oxe2x80x94, p=1 to 3, and q=1 to 3.
The diamine is prepared by reacting a cinnamic acid derivative represented by the formula (6-1): 
(wherein V represents H, CH3, F, Cl, Br or CH3Oxe2x80x94, and p=1 to 3) or a cinnamoyl chloride derivative represented by the formula (6-2): 
(wherein V represents H, CH3, F, Cl, Br or CH3Oxe2x80x94, and p=1 to 3) with a nitro compound having a hydroxyl group and represented by the formula (6-3): 
(wherein Y represents a trivalent organic group, and q=1 to 3) to afford a dinitro compound represented by the formula (6-4): 
(wherein Y represents a trivalent organic group, V represents H, CH3, F, Cl, Br or CH3Oxe2x80x94, p=1 to 3, and q=1 to 3), and then reducing the dinitro compound. In the formula (6-4), Y is a trivalent organic group, which is not particularly limited but may be selected from the following groups: 
wherein V represents H, CH3, F, Cl, Br or CH3Oxe2x80x94, r=1 to 3, n=1 to 20, and W represents a divalent organic group selected from xe2x80x94CH2xe2x80x94, xe2x80x94(CH2)mxe2x80x94Oxe2x80x94 (wherein m=1 to 15), and xe2x80x94(CH2)kxe2x80x94OCOxe2x80x94 (wherein k=1 to 20 (kxe2x89xa02)).
The dinitro compound is hydrogenated under the aforesaid reduction conditions to afford the diamine represented by the general formula (8): 
wherein Y represents a trivalent organic group, V represents H, CH3, F, Cl, Br or CH3Oxe2x80x94, p=1 to 3, and q=1 to 3.
Next, an explanation will be given to the polyimide composition production method (2) in which a diol-terminated polyimide oligomer is reacted with a dicarboxylic acid or dicarboxylic acid chloride having a cinnamoyl group to form ester linkage for polymerization, thereby affording the polyimide composition.
The polyimide composition wherein Win the general formula (1) is represented by the formula (1-a) is obtained by reacting a dicarboxylic acid represented by the following formula: 
or an acid chloride thereof with a diol represented by the following formula: 
for formation of ester linkage.
The polyimide composition wherein W in the general formula (1) is represented by the formula (1-b) is obtained by reacting a dicarboxylic acid represented by the following formula: 
or an acid chloride thereof with a diol represented by the following formula:
HOxe2x80x94D1xe2x80x94OH
for formation of ester linkage.
The polyimide composition wherein W in the general formula (1) is represented by the formula (1-c) is obtained by reacting a dicarboxylic acid represented by the following formula: 
(wherein V represents H, CH3, F, Cl, Br or CH3Oxe2x80x94) or an acid chloride thereof with a diol represented by the following formula: 
(wherein V represents H, CH3, F, Cl, Br or CH3Oxe2x80x94) for formation of ester linkage.
The polyimide composition wherein W in the general formula (1) is represented by the formula (1-d) is obtained by reacting a dicarboxylic acid represented by the following formula: 
or an acid chloride thereof with a diol represented by the following formula: 
for formation of ester linkage.
The polyimide composition wherein W in the general formula (1) is represented by the formula (1-e) is obtained by reacting a dicarboxylic acid represented by the following formula: 
or an acid chloride thereof with a diol represented by the following formula: 
for formation of ester linkage.
In the polyimide composition synthesizing methods, in which these diol-terminated polyimide oligomers are each reacted with the corresponding dicarboxylic acid or diacid chloride having the cinnamoyl group to form ester linkage for production of the polyimide composition, the resulting polymer tends to have a higher molecular weight where the diol is attributed to alcoholic hydroxyl groups than where the diol is attributed to phenolic hydroxyl groups.
An exemplary production method for a polyimide having a cinnamoyl group incorporated in an acid dianhydride residue thereof is such that an acid dianhydride having the cinnamoyl group is first reacted with a diamine.
Preparation methods for novel acid dianhydrides will hereinafter be described more specifically.
An explanation will first be given to preparation methods for novel acid dianhydrides having a cinnamoyl group and, for example, represented by the general formula (9): 
For formation of xe2x80x94COOxe2x80x94 linkage as B in the general formula (9), synthesis is carried out by reacting anhydrous trimellitic chloride with HOxe2x80x94C6H4(V)CHxe2x95x90CHCOOxe2x80x94 (wherein V represents H, CH3, F, Cl, Br or CH3Oxe2x80x94, which is hereinafter the same).
For formation of xe2x80x94OCOxe2x80x94 linkage as B in the general formula (9), synthesis is carried out by reacting hydroxyphthalic anhydride with ClCOxe2x80x94C6H4(V)CHxe2x95x90CHCOOxe2x80x94.
For formation of xe2x80x94Oxe2x80x94 linkage as B in the general formula (9), synthesis is carried out by reacting chlorophthalic anhydride with HOxe2x80x94C6H4(V)CHxe2x95x90CHCOOxe2x80x94.
For formation of xe2x80x94OEOxe2x80x94 linkage as B in the general formula (9), synthesis is carried out by reacting monohalogenated phthalic anhydride with a halogenated compound such as having Clxe2x80x94C6H4(V)CHxe2x95x90CHCOOxe2x80x94 and a diol represented by HOxe2x80x94Exe2x80x94OH (wherein E represents a benzene ring, a naphthalene ring, a biphenyl or xe2x80x94CmH2mxe2x80x94 (wherein m represents an integer from 1 to 20), which is hereinafter the same).
For formation of xe2x80x94COOEOCOxe2x80x94 linkage as B in the general formula (9), synthesis is carried out by reacting anhydrous trimellitic chloride with ClCOxe2x80x94C6H4(V)CHxe2x95x90CHCOOxe2x80x94 and a diol represented by HOxe2x80x94Exe2x80x94OH.
For formation of xe2x80x94OOCCHxe2x95x90CHxe2x80x94 linkage as B in the general formula (9), synthesis is carried out by reacting phenylene acrylic acid or phenylene acrylic chloride with hydroxyphthalic anhydride.
Similarly, for formation of xe2x80x94Oxe2x80x94EOCOxe2x80x94 or xe2x80x94Oxe2x80x94Exe2x80x94COOxe2x80x94 linkage as B in the general formula (9), synthesis is carried out by reacting a halogenated compound with HOxe2x80x94 for ether linkage or by reacting a carboxylic acid or an acid chloride with HOxe2x80x94 for ester linkage.
For formation of single bond as D2 in the general formula (9), synthesis is carried out by reacting hydroxyphthalic anhydride with ClCOxe2x80x94CHxe2x95x90CHC6H4(V)xe2x80x94.
For formation of xe2x80x94Fxe2x80x94OCOxe2x80x94 linkage as D2 in the general formula (9), synthesis is carried out by linking anhydrous trimellitic chloride to xe2x80x94C6H4(V)CHxe2x95x90CHCOClxe2x80x94 with a diol represented by HOxe2x80x94Fxe2x80x94OH (wherein F represents a benzene ring, a naphthalene ring, a biphenyl or xe2x80x94CmH2mxe2x80x94 wherein m represents an integer from 1 to 20).
For formation of xe2x80x94Fxe2x80x94Oxe2x80x94 linkage as D2 in the general formula (9), synthesis is carried out by reacting ClCOxe2x80x94CHxe2x95x90CHxe2x80x94C6H4(V)xe2x80x94 with HOxe2x80x94Fxe2x80x94Cl to afford Clxe2x80x94Fxe2x80x94OCOxe2x80x94CHxe2x95x90CHC6H4(V)xe2x80x94 which is in turn reacted with hydroxyphthalic anhydride.
An explanation will next be given to preparation methods for novel acid dianhydrides having a cinnamoyl group or a derived cinnamoyl group incorporated in a side chain thereof and represented by the general formula (10): 
For example, Clxe2x80x94K(OH)xe2x80x94Cl is reacted with cinnamoyl chloride or an acid chloride of a cinnamic acid derivative having H, CH3, F, Cl, Br, CH3Oxe2x80x94 or the like introduced onto a benzene ring of cinnamoyl chloride to afford a dichloride of the formula (10-1): 
wherein V represents H, CH3, F, Cl, Br, CH3Oxe2x80x94 or the like.
The dichloride of the general formula (10-1) is reacted with hydroxyphthalic anhydride to afford an acid dianhydride represented by the formula (10-A): 
wherein V represents H, CH31 F, Cl, Br, CH3Oxe2x80x94 or the like.
The acid dianhydride represented by the formula (10-A) can also be obtained by the following method.
A triol represented by HOxe2x80x94K(OH)xe2x80x94OH is reacted with cinnamoyl chloride or an acid chloride of a cinnamic acid derivative having H, CH3, F, Cl, Br, CH3Oxe2x80x94 or the like introduced onto a benzene ring of cinnamoyl chloride to afford a diol of the formula (10-2): 
wherein V represents H, CH3, F, Cl, Br, CH3Oxe2x80x94 or the like.
The diol is reacted with monohalogenated phthalic anhydride to afford the novel acid dianhydride represented by the formula (10-A).
Further, a novel acid dianhydride represented by the formula (10-B): 
is obtained by reacting anhydrous trimellitic chloride with the diol of the formula (10-2).
Further, CH3OCOxe2x80x94K(OH)COOCH3 is reacted with cinnamoyl chloride or an acid chloride of a cinnamic acid derivative having H, CH3, F, Cl, Br, CH3Oxe2x80x94 or the like introduced onto a benzene ring of cinnamoyl chloride to afford a compound represented by the formula (10-3): 
This compound is reacted with hydroxyphthalic anhydride for ester interchange to afford a novel acid dianhydride represented by the formula (10-C): 
The novel acid dianhydride of the general formula (9) obtained through the aforesaid reaction has the cinnamoyl group or derived cinnamoyl group incorporated in a main chain thereof, while the novel acid dianhydride of the general formula (10) has the cinnamoyl group or derived cinnamoyl group incorporated in a side chain thereof. These acid dianhydrides are useful as monomers for the novel polyimide compositions having photo-reactivity and heat-reactivity which are inherent in cinnamoyl group.
There will next be described methods for synthesizing the polyimide compositions.
In addition to the acid dianhydride represented by the general formula (9) or (10), other acid dianhydrides maybe used for the polyamide compositions having a cinnamoyl group or a derived cinnamoyl group according to the present invention. If the acid dianhydride represented by the general formula (9) or (10) is contained in a proportion of not smaller than 1% based on the total amount of the acid dianhydrides, the polyimide composition according to the present invention can exhibit properties inherent in the cinnamoyl group.
The novel acid dianhydride having the cinnamoyl group or derived cinnamoyl group incorporated in its main chain or side chain as represented by the general formula (9) or (10) is reacted with a diamine in an organic polar solvent to afford a polyamic acid, which is thermally and chemically imidized to afford the polyimide composition having the cinnamoyl group. The polyimide production method is the same as described above. The diamine having no cinnamoyl group and the other acid dianhydride to be herein used are the same as described above.
As described above, the novel polyimide compositions according to the present invention can be produced with the use of the diamine or the acid dianhydride having the cinnamoyl group. Other production methods for the polyimide compositions having the cinnamoyl group according to the invention will be described below.
An acid dianhydride having a hydroxyl group is reacted with a given diamine to afford an amic acid, which is then dehydrated for ring closure to afford a hydroxyl-terminated imide oligomer. The imide is reacted with a dicarboxylic acid derived from cinnamic acid or an acid chloride thereof for formation of ester linkage, thereby affording a polyimide composition having a cinnamoyl group or a derived cinnamoyl group in a main chain thereof, wherein X in the general formula (2) is, for example, represented by the formula (2-a), more specifically, Which comprises a monomer unit represented by the following formula: 
Further, where the hydroxyl-terminated imide oligomer is reacted with a compound represented by any of the following formulae: 
a polyimide composition having a cinnamoyl group or a derived cinnamoyl group, wherein X in the general formula (2) is represented by the formula (2-2), more specifically, which comprises a monomer unit represented by the following formula: 
can be obtained.
In another polyimide composition production method according to the present invention, trimellitic anhydride is reacted with a given diamine to afford an amic acid, which is then dehydrated for ring closure to afford a carboxyl-terminated imide oligomer. The imide is reacted with a diol derived from cinnamic acid for formation of ester linkage, thereby affording a polyimide composition having a cinnamoyl group.
More specifically, the carboxyl-terminated imide oligomer is reacted with a compound represented by either of the following formulae: 
(wherein V represents a benzene ring, a naphthalene ring, biphenyl or xe2x80x94CmH2mxe2x80x94 (wherein m represents an integer from 1 to 20), and F represents xe2x80x94CmH2mxe2x80x94 (wherein m represents an integer from 1 to 20)), a benzene ring or a naphthalene ring to afford the polyimide composition having a monomer unit represented by the general formula (1) and having a cinnamoyl group or a derived cinnamoyl group incorporated in a main chain.
Further, where the carboxyl-terminated imide oligomer is reacted with a diol represented by the formula (10-2): 
the polyimide composition having the monomer unit represented by the general formula (2) and having a cinnamoyl group or a derived cinnamoyl group can be obtained.
Any of various organic additives, inorganic fillers and various reinforcement agents may be added to the polyimide compositions thus obtained in accordance with the present invention.
The novel polyimide compositions of the present invention produced in the aforesaid manner have the cinnamoyl group and, therefore, exhibit heat- or photo-reactive and cross-linkable properties inherent in the cinnamoyl group in addition to various excellent properties inherent in the conventional polyimides. Therefore, the novel polyimide compositions of the invention will find new applications as excellent thermosetting resins and heat-reactive resins which are reactive at particular temperatures and/or at particular wavelengths.